METHOD OF MELTING NIOBIUM-CONTAINING STEEL Russian patent published in 2004 - IPC

FIELD: ferrous metallurgy; making low-carbon steels by means of vacuum oxidizing refining units.

SUBSTANCE: proposed method includes loading the charge containing carbon and manganese, melting, heating the metal in steel-making unit and oxidation refining at top blowing with oxygen and evacuation. Niobium-containing ferroalloy is introduced into metal after evacuation in form on niobium-containing powder wire at the following relationship: Q_p.w.Nb=100xQ_st x(0.288-0.018x(Mn)-10.178x(C)+8.989x[Nb]_req./[Nb]_p.w., where Q_p.w.Nb is consumption of powder wire ferroniobium filler (by filler), kg; Q_st is mass of molten steel, t: (Mn), (C) content of manganese and carbon in sample of metal before introduction of powder wire with ferroniobium, %; [Nb]_req. is required content of niobium in steel, %; [Nb]_p.w. is content of niobium in powder wire, %.

EFFECT: increased yield of good material; enhanced stability of steel teeming ladles.

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